Linalool prevents oxidative stress activated protein kinases in single UVB-exposed human skin cells

Ultraviolet-B radiation (285–320 nm) elicits a number of cellular signaling elements. We investigated the preventive effect of linalool, a natural monoterpene, against UVB-induced oxidative imbalance, activation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling in HDFa cells. We observed that linalool treatment (30 μM) prevented acute UVB-irradiation (20 mJ/cm 2) mediated loss of activities of antioxidant enzymes in HDFa cells. The comet assay results illustrate that linalool significantly prevents UVB-mediated 8-deoxy guanosine formation (oxidative DNA damage) rather than UVB-induced cyclobutane pyrimidine (CPD) formation. This might be due to its ability to prevent UVB-induced ROS formation and to restore the oxidative imbalance of cells. This has been reflected in UVB-induced overexpression of MAPK and NF-κB signaling. We observed that linalool inhibited UVB-induced phosphorylation of ERK1, JNK and p38 proteins of MAPK family. Linalool inhibited UVB-induced activation of NF-κB/p65 by activating IκBa. We further observed that UVB-induced expression of TNF-α, IL6, IL-10, MMP-2 and MMP-9 was modulated by linalool treatment in HDFa cells. Thus, linalool protects the human skin cells from the oxidative damages of UVB radiation and modulates MAPK and NF-κB signaling in HDFa cells. The present findings substantiate that linalool may act as a photoprotective agent against UVB-induced skin damages

Performance analysis of turbocharger effect on engine in local cars

The performance of a gasoline-fueled internal combustion engines can be increased with the use of a turbocharger. However, the amount of performance increment for a particular engine should be studied so that the advantages and drawbacks of turbocharging will be clarified. This study is mainly concerned on the suitable turbocharger unit selection, engine conversions required and guidelines for testing a Proton 4G92 SOHC 1.6-litre naturally aspirated gasoline engine. The engine is tested under its stock naturally aspirated condition and after been converted to turbocharged condition. The effect of inter cooled turbocharged condition is also been tested. Boost pressure is the main parameter in comparing the performance in different conditions as it influences the engine torque, power, efficiency and exhaust emissions. The use of a turbocharger on this test engine has clearly increased its performance compared to its stock naturally aspirated form. The incorporation of an intercooler to the turbocharger system increases the performance even further. With the worldwide effort towards environmental-friendly engines and fossil fuel shortage, the turbocharger can help to create engines with enhanced performance,minimum exhaust emissions and maximum fuel economy

Development of Malaysian urban drive cycle using vehicle and engine parameters

Vehicles travelling in actual urban areas are mostly in idle, low or medium speeds, which reflects engine part-load condition. These regularly visited engine conditions, in reality affect the fuel economy during actual driving. Thus, understanding the characteristics of the actual driving conditions will enable many other benefits besides legislation. This paper presents the development of a preliminary Malaysian urban drive cycle with the inclusion of the engine parameters and characteristics, acquired through an actual urban driving on numerous urban roads in Malaysia that represents the actual consumer’s daily driving experience. The actual engine parameters and its characteristics are integrated into the assessment measures in an attempt to formulate representable drive cycle and fuel consumption data. The initial drive cycle is composed of 17 sequences selected from the actual on-the-road conditions to represent the Malaysian urban driving. The average fuel economy of the established Malaysian urban drive cycle was then measured on a test bench using the same engine from the vehicle. The recorded fuel economy with Malaysian urban drive cycle is 8.5% below the actual Malaysian urban driving which is closer estimation to the actual driving compared to the current in-practice NEDC which shows to be 43.1% below the actual Malaysian urban driving. Thus, Malaysian urban drive cycle is better in representing the Malaysian urban driving conditions compared to the NEDC in terms of the average fuel economy measurements

Validation of an advanced assay for the diagnosis of inborn errors of cytotoxicity

The immune system provides protection against pathogens and malignancies. Therefore, genetic defects affecting the immune system can increase susceptibility to infections, may weaken the elimination of malignant cells or may lead to an exacerbated immune response. A rare but serious disease due to immune dysregulation is hemophagocytic lymphohistiocytosis (HLH). HLH is characterised by fever, hepatosplenomegaly, cytopenia, hyper-triglyceridemia, liver dysfunction and an elevated level of ferritin. Some HLH patients have a defect in cytotoxic immune cells affecting the degranulation of cytotoxic granules. When cytotoxicity is inhibited, cytotoxic cells remain bound to target cells, leading to prolonged activation of the cytotoxic cells. This in turn leads to increased release of cytokines and a vicious circle of cell activation. Without prompt intervention, HLH may be lethal, therefore timely diagnosis is essential. The standard diagnostic method is based on measuring the expression of CD107a, which follows efficient degranulation of cytotoxic granules. This method has its shortcomings, as it is does not prove whether the cytotoxic cells contains perforin and whether the target cell has actually been killed. For this reason, perforin expression has to be measured in addition in a separate flow cytometry test. We aimed to establish an approach using a single test analysing cytotoxicity which would allow to confirm the diagnosis of inborn errors of cytotoxicity in a faster and more reliable way. To this end, a europium release cytotoxicity assay was established. Target cells were loaded with the non-radioactive acetoxymethyl ester of the fluorescence enhancing ligand (bis(acetoxymethyl) 2,2':6',2"-terpyridine-6,6"- dicarboxylate (BATD) (Perkin Elmer). Cells used for this assay were peripheral blood mononuclear cell (PBMC), containing cytotoxic natural killer cells, which functioned as effector cells and K562 cells, a lymphoblastic cell line that served as target cells. In the assay, the target cells are loaded with a fluorescence enhancing ligand. When these cells were killed, the ligand was released and formed a fluorescent chelate with europium. The fluorescence intensity in the supernatant corresponds to the amount of target cells that were lysed. We first determined the ideal assay conditions by titrating different effector: target cell ratios, namely from a 2:1 (Target: Effector) ratio stepwise down to a ratio of 0.125:1. 3 Here we show, that the best condition to perform this assay was with at least 1x10 5 K562 cells per well in a 96 well plate with a 1:1 Target: Effector ratio, and an incubation of 2 hours. After having optimized the conditions of the cytotoxicity assay, we tested whether the expression of CD48 on the surface of K562 cells would influence the killing. We indeed observed increased killing of cells expressing CD48. However, we did not observe a significant difference in killing when comparing cells with high with those with intermediate CD48 expression. In conclusion, we were able to establish a rapid one-step assay for cytotoxicity which will allow to analyse patients’ cells with suspected inborn errors of cytotoxicity in a faster way than with the currently used NK cell degranulation assay, which needs to be combined with protein expression analysis of perforin. Nevertheless, further optimization of the assay is needed to be able to see more subtle differences in the susceptibility to be killed as there may be between cells expressing intermediate versus high levels of CD48

Synthesis, structural and optical properties of Mn doped ZnO nanoparticles and their antibacterial application

In the present investigation, MnxZn1-xO (x = 0.05, 0.075 and 0.1%) nanoparticles have been synthesized by simple precipitation method. Their structural, morphological and optical properties were examined by using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX), High resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Differential scanning calorimetry (DSC) and UV-Visible spectroscopy. The Powder X-ray diffraction studies confirmed that the manganese doped ZnO have a single phase nature with hexagonal wurtzite structure and Mn successfully incorporated into the lattice position of Zn in ZnO lattice. The FESEM and HRTEM images are coincided with each other for aggregation of particles in nature. The elemental analysis of doped samples has been evaluated by EDX. The antibacterial activity of Mn doped ZnO nanoparticles has also been examined

Preparation and Characterization of Ag doped ZnO nanoparticles and its Antibacterial Applications

In the present investigation, AgxZn1-xO nanoparticles (x = 0.05, 0.075, and 0.1%) have been successfully synthesized by precipitation method. The synthesized AgxZn1-xO nanoparticles were characterized by X-ray diffraction analysis (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX), High resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and UV–visible spectrophotometer. The XRD studies revealed that the Ag doped ZnO nanoparticles in hexagonal wurtzite structure. The FESEM and HRTEM images show that the presence of aggregated nanoparticles. The EDX spectrum confirmed the present metals in AgxZn1-xO nanoparticles which indicated the purity of the sample. The FTIR and Raman spectrum indicates that the present functional groups and crystalline quality of Ag doped ZnO nanoparticles. The optical properties were measured by using UV–Vis Spectrophotometer. The antibacterial activity of the samples are examined and also compared with standard drugs

Seismic Analysis of a Partially-Buried Drinking Water Reservoir

This paper describes the details of the seismic analyses undertaken to retrofit the Kersland drinking water reservoir in Vancouver, British Columbia, Canada. The reservoir has a storage capacity of about 67 million litres, measures approximately 100 m by 150 m, and is partially buried. The walls are supported by above-ground soil berms. Seismic upgrading of the reservoir required an assessment of the loads imposed on the perimeter walls of the reservoir due to the design seismic event. The problem of soil-structure and structure-fluid interaction during seismic loading is complex, and could significantly increase the lateral forces on the reservoir wall. Seismic response analysis of the soil-structure system was carried out using the finite element program FLUSH. Modeling the effects of water under earthquake loading was included as convective and impulsive forces using a series of lumped masses attached to selected structural beam element nodes and a horizontal spring. The bending moments and shear forces in the reservoir wall, and seismic earth pressures exerted by the soil on the wall were obtained for detailed structural analyses. The results of FLUSH analyses were compared with the available closed-form solutions

Effect of Turbine Upstream Geometry on Pulsating Flow and Turbocharged Si-Engine Performance

The pulsating exhaust flow propagates through the exhaust line upon opening of exhaust valves while carrying a high amount of energy (high pressure and temperature). The amount of energy delivered to the turbine could be affected by turbine upstream geometry along with the propagation. Therefore, in this study, the impact of the turbine upstream geometry (diameter, length of exhaust runner, and exhaust manifold volume) on pulsating flow and engine & turbocharger has been investigated using 1D engine simulation packages, AVL-BOOST. A validated 1-liter 3-cylinder SI-engine model was utilized as a base engine model. The simulation captured how different geometry influences the pulsating pressure profile and the impact on system-level performance and behavior. The current research highlighted that the exhaust manifold volume is strongly associated with exhaust resistance, scavenging, pulsation, knocking, and fuel economy. By minimizing unnecessary volume in the exhaust manifold, it presents high potentials to improve low-speed torque (∼15 %), fuel consumption (∼2.4 %), brake thermal efficiency (∼1.4 %), scavenging and knock resistance against the baseline model.©2023 Springer. This is a post-peer-review, pre-copyedit version of an article published in International Journal of Automotive Technology. The final authenticated version is available online at: https://doi.org/10.1007/s12239-023-0044-3fi=vertaisarvioitu|en=peerReviewed

Effects of Earthquake Induced Liquefaction of Sediments Stored Behind Concrete Dams

Earthquake induced liquefaction of sediment stored behind dams can give rise to high uplift pressures which could endanger their safety. The uplift pressures depend upon the permeability and compressibility of both the sediment and the foundation and are controlled by Biot\u27s equation. Uplift pressures are computed for a single dam and foundation with a range of properties. The results show that for the conditions analyzed, the uplift pressures are largely controlled by the foundation permeability with the largest uplift pressures occurring for the highest foundation permeability. The possibility of liquefied sediment flowing into fissures in the foundation rock is also considered and can result in much higher predicted uplift forces. This condition is only likely to occur for a foundation rock of high permeability

Measurements and Predictions on the Elkhart Greek Culvert

This paper describes field measurements and analysis carried out on the Elkhart Creek soil arch culvert structure in British Columbia, Canada. The structure has a span of 13.4 m, a rise of 7.3 m, and a soil cover of 9.6 m. The original structure collapsed during backfilling in October 1987. A new structure of the same design was built in the Fall of 1989, and because of controversy regarding the design thrust value, it was instrumented to measure thrust, moment, and displacements in the arch. Displacements and stresses in the soil were also measured. The measured thrust values were much lower than expected and indicated that significant positive soil-arching occurred. A nonlinear finite element analysis of the soil-structure system was carried out simulating the construction procedures used, and the computed response compared with the measurements. The computed and observed responses were in reasonable agreement in terms of thrust, moment, displacements and soil stresses provided an allowance was made for slip at the bolted connections